This book is just an introduction to the science of psychology. Psychology is the scientific study of behavior and mental processes. It is a tough subject, but it is interesting, fascinating and challenging. It is interesting because it is about people, 'us' and 'others'. All of us are eager to know why we think and act the way we do and why others behave the way they do. It is challenging because, in spite of several centuries of hard work, what we know about the human mind and behavior is pretty little. But do not be discouraged, it is the fate of all sciences including physics and physiology. Physics does not know everything about the physical world and physiology has not completely unraveled the mysteries of the human body. So, it is not surprising that psychologists are struggling to understand the marvels of human mind. However, what little we know about mind and behavior is encouraging enough to prod us to move forward. Psychology promises to help you to understand others and yourself; not that you will be able to understand yourself and others fully with the existing knowledge of psychology. That is a difficult task and a distant dream. The complexities and contradictions of the human mind cannot be easily understood and explained. Psychology can only help you to take the first step toward that end. Toward this end, you will find a number of theories, research studies and isolated facts presented throughout this book. Study of these facts may help you to have a better understanding of your own thoughts, feelings and behaviors as well as those of others.